Derby boosted their play-off ambitions with a rare win in London, 2-1 at lowly Charlton.
Macaulay Gillesphey's own goal and Bobby Clark's second-half strike made it back-to-back away wins for John Eustace's side despite a goal for the hosts from Tyreece Campbell and a late red card for Matt Clarke.
It was Derby's seventh victory on the road this season, and their first in the capital since 2021.
Their preparations were hindered in the warm-up with goalkeeper Jacob Widell Zetterstrom pulling out of the team 25 minutes before kick-off with a virus.
Much-travelled 37-year-old Richard O'Donnell was promoted from the bench for his County debut and a first Championship appearance since May 2017, when he lined up for Rotherham against the Rams.
In the Charlton starting line-up for the first time was Lyndon Dykes, who joined from Birmingham last week in a bid to cement his place in Scotland's World Cup squad.
The striker had an early chance to make an impression when he met a cross from Campbell, but his header flew narrowly over.
Moments later Dykes' strong run forward teed up a chance for Campbell, who cut inside before firing across goal and wide.
But Derby went ahead in the 17th minute when Patrick Agyemang reached the byline and drilled in a low cross which Addicks defender Gillesphey could only divert into his own net.
Clarke was lucky not to see red in the first half after he was robbed by Miles Leaburn on the edge of the box and then, in trying to recover, brought down Dykes.
Referee James Linington decided a yellow card would suffice, and O'Donnell saved the subsequent free-kick from Sonny Carey.
Corey Blackett-Taylor, recalled by Eustace to face his former club, almost doubled the lead when he raced through on goal but his finish was too close to home keeper Thomas Kaminski.
Ben Brereton-Diaz could have grabbed a second before half-time but dragged his shot wide of the far post.
After the break Agyemang poked a Joe Ward cross wide and Brereton-Diaz's shot was held by Kaminski.
The goal the visitors had been threatening arrived on the hour when former Liverpool youngster Clark latched on to a neat Brereton-Diaz through-ball and finished past Kaminski.
Charlton pulled one back when Campbell, their liveliest player on the night, curled home from the edge of the box.
O'Donnell then came to Derby's rescue with a superb late save from Gillesphey's free-kick while the Rams held out despite Clarke's dismissal, a second booking for a foul on Kayne Ramsay, five minutes from the end.
Charlton's Nathan Jones:
"I'm disappointed really, I felt the goals were avoidable.
"We've struggled to keep clean sheets and defend the way we want to and that's what has cost us.
"Second half I thought we were excellent. They had one chance and scored and that's the disappointing thing."
Derby's John Eustace:
"I'm very pleased. I thought the effort the group put in was superb.
"It's a long, relentless season so it's really pleasing to see how the group has matured and if you do the right things you get the rewards.
"We just want to be competitive and see where that takes us."
